Method of manufacturing heat exchangers



J. KARMAZIN METHOD OF MANUFACTURING HEAT EXCHANGERS May 25, 193 7.

3 Sheets-Sheet 1 Filed Dec. 4, 1935 WW R May 25, 1937. J. KARMAZIN METHOD OF MANUFACTURING HEAT EXCHANGERS Filed Deb. 4, 1955 a Sheets-Sheet 2 INVENTOR;

May25, 1937. J. KARMAZIN 2,081,303

METHOD OF MANUFACTURING HEAT EXCHANGERS I Filed Dec. 4, 1935 3 Sheets-Sheet 3 INVENTOR;

Patented May 25, 1937 PATENT oFFi MIETHOD OF MANUFACTURING HEAT EXCHANGERS John Karmazim; Huntington, Ind., 'assignor to Karmazin Engineering Company, acorporation of Michigan Application December 4, 1935, SeriaiNo. 52,818 4 Claims. (cl. 113-118) This invention relates to heat exchangers which may be used on refrigerating apparatus or the like.

It is an object of this invention to provide a novel heat exchanger and a novel method of manufacture of such a heat exchanger.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a view, partly diagrammatic andpart ly in cross-section, of a refrigerating apparatus including a preferred form of my novel heat-exchanger; v

Fig. 2 ,is a view taken transversely to Fig. 1;

Fig."3 is an enlarged view somewhat similar to Fig. 2, but showing the exchanger in the process of manufacture;

4 is a view taken along the line 4-4 8 Fig. 5 is a view somewhat similar to Fig. 4. showing a slightly modified form of manufacture;

Fig. 6 is a perspective view of a blank of material from which tubes may be made; Fig. 7 shows an early of tubin8;- Fig. 8 shows an advanced step in the manufac- 30 ture of tubing; 1

Fig. 9 shows a portion of'a fin before the tube has been applied;

Fig. 10 shows the finwith the tube applied thereto;

'35 Fig. 11 shows another step in the manufacture of the tube; v 4

Fig. 12 is a cross-sectional view of the material taken along the line 12-12 of Fig. 11';

Fig. 13 is a cross-sectional view taken along the line l3-l3 Fig. 11, but showing only the material;

- Fig. 14 is a perspective view,- somewhat similar to Fig. 10, but showing, a jmodifled form of the 1 invention; and 4.5 Fig. 15 shows a modified form heat exchange This invention is directed'to the manufacture of. heat! exchangers such as condensers, evapoof tube for the raters, ators and the like. Thus, as indicated in Fig.1, heat exchanger may be a'condenser,

although it is to be understood that any other type of heat exchanger may embody features of my in- "vention. I

In Fig. 1, a-refrigerating system is indicated somewhat diagrammatically. It includes a comstep in the manufacture pressor 10, which discharges compressed refrigerant through line II to the condenser l2. The condensed refrigerant fiows through the line I3 to the evaporator I placed 'in the cabinet or other. space to be cooled l5. The evaporated re-, frigerant returns through the line 16 to the compressor ill. The compressor Ill may be driven by an electric motor l1, and the electric motor may -be controlled in accordance with refrigeration conditions. Thus the temperature in the cabinet 15 acts upon a thermostatic bulb l8, which actuates a snap switch l9 through the medium of expansible. bellows 28, the switch 13 starting the motor and compressor when the temperature in the cabinet reaches a predetermined high limit and stopping them when the temperature reaches a predetermined low limit. 'The particular condenser shown in Fig. 1 is adapted to he s pported with the brackets 2| and 22 uppermost, hese brackets together with the brackets 23 and 24 being secured to any suitable support. The arrangement is'such that airmay be induced by convection or by forced draft over the fins 25 which are in contact with the tubes 26. The battery of tubes 26 is connected to a header 21- at-on'e end and to a liquid receiver 28 at the other end, the liquid receiver being provided with a header 29. The header 2'! includes/a semi-circular metal sheet 30 and a substantiallywhich are adapted to be secured to the cylinder 28 by welding, as hereinafter described. A tube 31 is connected'at the bottom of header 29 and extends to the top 38. Gaseous refrigerant enters from the pipe ll' through the nipple 40 in the upper part of header 21 and the gaseous refrigerant fldws into the tubes 26 where the refrigerant is condensed. The condensed refrigerant flows to the lower part of the condenser either through .the header 23 or through the header-.21, the liquid finally rising above the lower end 31a of the tube 31. The head pressure'causes the liquid to enter ows out the nipple 4i and through the the evaporator. The presence of the tube 31 prevents liquid refrigerant contained in the tube 31 and be discharged over the edge 38 I into the receiver 28 from whence the liquid refrigerant "pipe 13 t v the receiver 28 from retin'ning to the header 29.

This condenser may be used in a different position, with the flanges-22 and 24 lowermost, in which case the nipple 4| may be placed at the point 4| a and the tube 31 may be omitted.

The tubes 26 and the fins 25 are secured to each other and to their respective headers as more clearly indicated in Figs. 3 to 14 inclusive. The tubes are formed from flat sheet metal stock in strip form of the character shown in Fig. 6. This stock is initially formed with flanges along the edges by suitable rollers into the shape shown in Fig. 7 orl2. Thereafter it is further bent into the shape shown in Fig. 8 or 14. The tubes may have the edges and 5! relatively flat and abutting each other as shown in Fig. 8, or one of the edges 50a may be provided with a slightly curled flange 52 which fits over the flange 5| as indicated in Fig. 14. In either form, the tube may be bent by a die of the character shown in Fig. 11. After the stock hasbeen given an initial shape either as shown in Fig. '7 or 12, it. is drawn through the die 53, which is tapering in section. Another die 54 is placed within the die 53 and the tubing is drawn through the die thus receiving the form either shown in Fig. 8 or Fig. 14.

It may be cut into lengths suitable for the particular heat exchanger being manufactured.

After the tube has been cut to the properlength, the fins 25 are fitted over the tubes with the flanges 55 fitting tightly over the tubes. Wires 56 of bonding material are placed within the tubes and thereafter the assembly is run into a welding oven having a reducing atmosphere. During the welding operation, the bonding material melts and forces its way between the flanges 50 and 5| or 50a and 5| and bonds the flanges 55 to the tubes 25. When the material is sheet steel, the

wires 58 may be of copper or copper alloy, and the capillary action is such that the copper will rise in the tubes if the tubes are placed in the position shown in Fig. 4 or will flow downwardly if the tubes are placed in the position shown in Fig. 5.

The. entire assembly may be welded together in the welding oven. In this case; additional pieces of bonding material may be placed in the headers 21 and 29 and in the receiver 28 so .that

the ends of the tubes are welded to the headers andthe edges of the headers are welded in fluidtight relationship and the ends 34 and 35 are hermetically sealed to the tube 28.

A slightly modified form of tube is shown in Fig. 15. In this case the metal sheet is bent into the form-there shown which includes a semi-circular portion 60 and touching portions 6| and 62. Fins are adapted to be placed over this tube in a manner similar to that heretofore described and the same may be assembled by providing bonding wire 63 as heretofore described.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. The method of constructing a heat exchanger which comprises placing perforated fins over an open seamed tube, placing bonding material inside said tube and heating the assembly to cause the bonding material to flow out between the engaging surfaces of the seam and to bond said fins to said tube.

2. The method of manufacturing finned tubing which includes placing apertured fins over open seamed tubes, placing bonding material within said tubes and heating the assembly to cause the bonding material to flow by capillary action between the engaging surfaces of the seam and between said tubes and fins.

3. The method of forming finned tubing which includes placing fins having apertures corre sponding to the shape of open seamed tubing v over said tubing, placing bonding material within said tubing and heating the assembly to cause the bonding material to flow out at the seam and between the fins and tubing.

4. The method of forming finned tubing which includes placing flns having apertures corresponding to the shape of open seamed tubing over said tubing, placing bonding material within said tubing and heating the assembly to cause the bonding material to flow out at the seam and between the flns and tubing, the bonding material being in the form of longitudinal strips 01; wires.

- 1 JOHN KARMAZIN. 

